09 September, 2009

Installing fenders on some bikes results in toe clip overlap (TCO). When you turn the front wheel in a tight, slow-speed turn, your toe clip, or toe, can hit the front fender. This is especially common on smaller frames and frames with steep head tube angles. I've owned several larger racing bikes with TCO, but it has never really bothered me. I simply watch the position of the crank when turning at slow speed. In fact, the only time I remember experiencing it is when slowly circling while waiting for someone. Some folks, however, really hate TCO.

One way to give yourself a little extra toe room is to replace the eyelet bolt on the front fender stay with an r-clip. This makes a lower profile attachment resulting in an extra 5mm of room. You can also drill a second hole and move the stay to a lower position. This latter fix doesn't look great, but it works. Finally, if you have smaller feet it's a good idea to try smaller toe clips.

Fortunately, VO frames all have reasonably long top tubes and, being low trail, generous rake. This will minimize TCO as compared to most modern frames, but there still may be some on smaller sized frames.

Do you think TCO overlap is important enough to make compromises in frame geometry to eliminate it? Or is it better to have the best possible handling and live with TCO on a small frame?

52 comments:

I ride a track bike that I've fit with fenders and use large toe clips, it's also fixed gear so there's no getting around positioning pedals. but I've only struck my fender maybe once or twice? I think some people make it out to be a bigger problem than it is, another tip would be just tip your toe downward if you're riding that slowly.

Speaking of the rake on the new frames, are you going to post the geometry specs? I'm also interested in what the thickness of the tubes will be.

Toe Clip Overlap is a problem for me as I ride on rail trails that have access gates at road crossings. The gates require 2 low speed sharp turns to navigate and I have wobbled and tipped at least twice due to the toe clip catching on the fender strut. I am still looking for a good solution.

The first time I posted a (fendered) bike pic on line, someone e-mailed me that TCO must be a bummer.

I had to look up the term.

In other words, never been an issue for me.

Only one of my bikes (ironically not the one mentioned above) has TCO. Like Chris, I try and calibrate my pedal rotation to turning. Where I cannot, I bump the fender a bit. I really do not need toe clips on this particular bike and could take them off if necessary. No big deal.

I absolutely hate toeclip overlap. One of the reasons why my favorite bike I've owned is the Miyata 610 is because it is very generous in that department. I don't use toelips but I still get overlap with my Cross Check.

The importance of TCO depends on how the bike is used. On a pleasure-only bike, it may make no difference. On a city bike, which has to make a lot of low-speed turns, often with little notice, it can be a major annoyance. Make that city bike a fixed gear, and TCO may become dangerous. As Bicycle Quarterly points out, any such interference can pose a danger to a cyclist at the edge of exhaustion -- but few riders go there.

Thanks for the tip! I have over an inch of TCO (though I don't use clips) on my touring Cannondale, and I need all the help I can get. A little TCO is no problem, but it's a perfect storm on this bike -- small frame, short top tube, 35 mm tires, VO fenders, and probably a low fork rake. This geometry should have smaller wheels.

I agree with everyone except when it comes to very small bikes. To me, it just doesnt make sense to put 700's on a frame smaller than 50cm. Along with being ugly, it seems really unsafe. I have a 47cm with 700's and calling it TCO is a joke, it is more like Whole Foot Overlap (WFO). A terrible design that should not have been made.

I'm a former USCF Cat 1 racer, and as I recall, ALL of my road racing bikes (Colnagos, Cinellis and Litespeeds) had TCO.

For me, it's a total non-issue that is best dealt with via a minor adaptation in bike handling at slow speeds--similar to the adaptation one needs to make in not cornering with the inside pedal down in a high speed tight lean.

The ONLY argument I can think of that might justify making a design modification on VO frames to eliminate TCO is that the French Constructeurs tried to eliminate it, so for reasons of tradition, the market might tend to place a premium on bikes that don't demonstrate TCO.

In dealing with the consequences of brash decisions from countless motorists, quick and sharp maneuvering is necessary when commuting. Not wiping out in traffic can make the difference between life and death! No TCO for me, thank you very much!

Ah yes, and regarding the Cross-Check, I've ridden a 58cm that had terrible TCO with 175mm cranks, but have also ridden a 60cm with 180mm cranks and ample toe room! Many factors involved with the dreaded TCO! I don't race or hit the track, so yes, it matters to me.

Had plenty of TCO on my messenger bike, and it never caused me any problems at all. Back then, I thought that was just how bikes were. I guess it's a nice thing to avoid if possible, but not a priority for me.

That said, I wish it were possible to know the TCO risk associated with a specific geometry and build. Like a TCO calculator that could use these numbers: the Front-Center measurement, tire diameter, fender+/- and crank arm length.

I'm 5'2", and since I don't live in dreamland, all my bikes have had 27 inch or 700c wheels. To be absolutely, totally honest, until last year, during decades of riding, I never looked for nor noticed any TCO. I always assumed that a shorter person has shorter feet that compensate for the shorter top tube. I've always ridden fenderless though.

But last year, I got some new SPD-compatible shoes that seem to have an extra bit of length at the front of the sole. I noticed it only when I actually did almost fall in traffic as I was taking off from a stop, and my wheel turned.

Anyway, I would prefer to not have any TCO, but not to the point that I would want to be riding some oddball wheel size that nobody else does. It's easy for taller people to suggest shorter people ride bikes with children's sized wheels, but it's not very practical in the real world. Trust me, I know. I've been a 5'2" cyclist since I was about 18, and that was 40 years ago.

TCO actually can be dangerous with fenders. Not really a big deal without fenders, as noted.

It doesn't happen often . . . but I have caught a fender with the tip of a shoe, while taking off at a light, driven it into the tire sideways, the fender somehow twisted, warped and crumpled, and the wheel locked and I went down in a second. It was a good bike, a decent metal fender, and I wasn't tired at all or going fast. If I had been going fast, I would've been hurt. This only happened that once, but it was pretty violent and it wasn't fun. It might be a once in a million thing, maybe if I had checked the clearances more carefully, but . . . It's for this reason that the European fenders often come with detachable clips, and I believe in them.

"cm" is right. The remedy is simple. Fit smaller wheels on smaller frames. Problem solved. Case in point: the Surly Long Haul Trucker. The smaller frames fit 26" wheels and the geometry's pretty laid back, so there's minimal overlap. And there's no performance penalty to downsizing that I can see. I've been riding a short LHT for a year now, and I not infrequently dust roadies pushing tall and skinny carbon-frame ultrabikes -- despite my having two racks, full fenders, cyclocross tires, an overstuffed bar bag, and (often) 30 pounds of groceries in my rear panniers.

Of course, I don't see too many of those roadies out riding the Adirondack foothills in January. But I am. Maybe that has something to do with it.

tco matters to me and to most others i know who ride in major cities...the ability to turn on a dime, zig and zag, hop a curb, etc., and negotiate the stupidity of the car roads in the big city – with cars often sitting in MY way slowing ME down – is valuable.

the argument here is weak re: handling -- it could be juast as easily asserted that too much is made of a bikes "handling." tco could be fixed easily, and the rider will adapt to the changed handling (if they notice at all.) the nature of human cognition, and of the brain's plasticity in adapting to felt changes/somatic orientation in space, make the handling issue moot, given there is always a *range* within what consitutes good handling, not just a fixed point; or a singular geometry.

of course, as jobst brandt points out, cyclists just love myth and lore, and doubtless tco is in the same league as the idiocy of "planing"...

What a topic! I've got a 5mm toe clip on my 54cm CrossCheck, my Audax bike that has seen 300+km a day rides. It wasn't there before but ... a TA cyclotouriste crank with very tight Q factor, 35mm Marathon Supreme's, fenders and the cleat on the shoe is positioned as far back as possible. All these factors are against not having toe clip. One after another it was inevitable on the 54mm CrossCheck which is a super tight frame to begin with using 700c wheel size. I've also got a Pletscher zoom rear stand mounted and heel clearance is miraculous.

I can survive with the toe clip seeing as it's very small amount, I can actually point my toe down/forward a bit and the clip is gone. The handling of the frame/bike setup is marvelous, you can turn super tight circles but also have highly stable descents at 50+kph. That thrilled me. I noticed I had shimy the other day on a stone chip surface road at a certain speed while riding "no hands". I've never had it before and I can't replicate it again so I suspect is was an odd weight in the bar bag or another mysterious item. The shimy was no at all violent and kind of pleasant but I was surprised with such a tight wheel base. Toe clip can provide a shock to the rider, I suspect that's why it's most unliked, but you get advantages with it too on borderline wheelsize bikes. Any smaller than 56cm top tube I'd say 650 wheel size is best, but 700 on 56 seems to be some sort of marvelous combo, if your lucky.

Chris: When you say no good 26" road tires, are you referring to faster tires?

Some of Schwalbe's excellent touring and City tires, such as the Marathon, Big Apple, and Kojak come in 26" variations. In fact, I am putting together a bike to use the 26" Big Apples as the 29ers were just a little high for my 5' 11".

Schwalbes are not at the level of the 650b Grand Bois offerings in comfort and appearance, but they are durable and have very low resistance.

Better to learn to ride than to compromise design to accomodate clumsiness... though if it gets too bad with really small frames then smaller wheels make sense (they do anyway). 26" and 24" are both pretty common, so no need for obscure sizes.

My city fixie has a fair bit of overlap and it's still safe and manageable. You learn how to deal with it and it becomes automatic.

Chris, your point about Berthoud fender mounts makes no sense at all. The Berthoud fender stay is actually flattened as it rounds the curve of the fender. It is bolted there through the fender. The eye bolts of Honjos and VO fenders allow the fender stay to remain proud of the fender surface and the bolts themselves protrude from the fender much further than those on Berthoud fenders.

The traditional French-style stays (like VO's and Honjo's) WITH R-CLIP are the lowest profile because the screw head is even with the stay. The Berthoud-style stays are next best because the screw head sits atop the stay, sticking out a little further. An eyelet bolt sticks out even further. The difference is only a few mm.

Minor TCO with fenders is annoying in a cyclotouring bike, but not a danger.

Larger amounts of TCO with fenders(more than a centimeter or so) can be difficult in unplanned maneuvers, no matter how skilled or experienced the rider. The standard eyebolt makes it worse, as it provides a sharp edge to catch one's shoe. It is a bad idea, and worth making adjustments to a geometry (in my opinion) in order to avoid it. Thankfully, if one has appropriately designed the bike to begin with, these adjustments are small and won't have much effect on the function of the machine (like adding 5mm to the top tube--we're not talking about gross mismatches between required top tube length and wheel size, like a 47cm bike with 700C wheels and fenders).

@CM, Computing TCO isn't hard at centerline. Start with a front center calculation (fun with pythagoras, but not hard if you've got the geometry specs), subtract off the length of the crank, the projection of the shoe/toe clip forward of the pedal centerline, the outer radius of the wheel, the clearance from wheel to fender, and the depth of the fender mounting hardware. You can measure all of these items.

Calculating TCO potential at the off-centerline location of the foot is a bit harder, as the wheel sweeps out an arc and therefore provides additional clearance (and the fork rake complicates matters), but still a spreadsheet calculation if you know the tread width of your bike. In practice, it is around a centimeter of additional clearance.

In General, 615-620mm gets average size folks out of the woods on 700C bikes with 28mm tires, and 610-615mm on 650B machines. Big feet and "arch cleat" placement will require additional front center.

First, as far as I'm concerned, there is no such thing as "minimal toe clip overlap". If you have TCO, you have it, no matter how minimal it is. It's like being a little bit pregnant.

While I have nothing against 650B as such, outside of the internet, it's an oddball, virtually unavailable tire size. Nobody has that, even in a large metropolitan city. I don't want to be dependent on ordering things via internet. I don't even have a credit card. I want to be able to walk to an LBS and buy a couple of tires. But leaving even that aside, if you have TCO with an unfendered 700c wheel, you probably are still going to have it with a fendered 650B wheel... so, problem not solved. You might even still have it without the fender, if you take advantage of the puffier 650B tire widths. It's not too different with 26 inch wheels either.

"First, as far as I'm concerned, there is no such thing as "minimal toe clip overlap". If you have TCO, you have it, no matter how minimal it is. It's like being a little bit pregnant."

Sorry, but that is simply not true. With minimal TCO you will simply brush the tire or fender lightly. If TCO is more severe, the tire may not make it past your foot. So yeah, there are degrees of TCO.

I've always managed to compensate for it when needed with crank position relative to front wheel position. It's more of an issue when doing slow maneuvers with a fixed-gear, but still not a deal breaker. I'd rather have a more comfortable, responsive bike for 99% of the riding, and deal with a little TCO.

Complaining something is available only over the internet in 2009 is just a little anachronistic, wouldn't you say?

Moreover, 650b tires and rims are available at bike shops in such U.S. metropolitan areas as NYC, Boston, Chicago, Portland, Seattle, SF Bay area, LA, and, of course from Velo-Orange in bustling Annapolis, MD.

I don't know if I count as riding lots, about 3000 miles average for the last 35 years, or if I have good, indifferent or poor handling skills, but I don't like TCO. For the vast majority of the time it is not an issue, my obviously meagre bike handling skills are good enough to mitigate any problem. However, on occasion I do find myself in a position where I have to pedal through the TCO window of opportunity. On my race geaometry bike it is a bit of a faff. On my fixie and on my old tandem it is down right dangerous. On my newer tandem (I was going to saw 'new' until I reasiles it was 16 years old!) not having TCO is one less thing to worry about.

If you can build a bike without TCO and with the required handling and other design features, why do it?

"No really superb 26" road tires"? I'll have to defer Chris' judgment in this matter. "Superb" isn't a word that trips easily off my tongue. But "competent" is, and my 26" Marathon Cross tires are that and more, both on and off the asphalt. I can spin along at 19-22 mph on the valley flats (provided that the headwinds don't rise much above Force 3, that is), negotiate dirt forest tracks and jeep trails with reasonable aplomb, and ride over broken beer bottles without fear of flatting. That'll do me. I don't ask more of any tire.

The Crosses are NOT good on ice, of course (but I have studded tires for winter riding). And they have one other shortcoming: They're noisy, emitting a constant, harsh buzz when ridden at speed on hard-surfaced roads. I chased down a couple of triathletes-in-training last weekend. (They passed my wife and me as we were dawdling up the backside of White Hill. I couldn't resist rising to the bait.) When I caught them up after a short but spirited pursuit, my buzzing tires announced my approach, impelling the rearguard rider to shout a warning to his companion to the effect that they were about to be run down by a logging truck. Only then did he trouble to look over his shoulder -- real roadies disdain mirrors, I guess -- and saw, not a careering logging truck hellbent on destruction, but a lone cyclist on a steel bike, keeping pace with him at a distance of some thirty feet. (My wife was perhaps a quarter mile farther back. She has more sense than to give chase to other cyclists. Someday I'll learn.)

Come to think of it, though, "buzzing" is too mild an epithet to describe these otherwise competent tires' acoustic signature. "Grating" -- now that's the word. Marathon Cross tires undoubtedly grate on sensitive ears when ridden on hard surfaces, though the noise is never loud enough to mask the roar of honest-to-god logging trucks. Or churring red squirrels, for that matter. Is the noise annoying? Yes. Sometimes. But it's a mighty small price to pay for these tires' many other virtues.

When Less Is More

An anonymous writer dismisses the idea of "minimal toe clip overlap," claiming that "If you have [it], you have it." That's indeed succinct, not to say pithy. Unfortunately, it is also somewhat misleading. My working definition of "minimal toe-clip overlap" is, appropriately, minimalist: If the overlap is so small that a plastic-fender-encumbered wheel can swing through its arc without the fender contacting the tire and bringing the rider crashing down, the overlap is indeed minimal. Otherwise not.

I've experienced both types of overlap -- minimal and the other kind. There IS a difference, believe me. And it's painfully obvious.

Vive la Femme!

Diana is right. Despite my occasional misadventures on bikes exhibiting the wrong sort of toe-clip overlap -- that's the non-minimalist kind, of course -- I'm inclined to agree that this concern ranks rather low on the scale of cyclist's worries. There are dogs in the world, after all. And logging trucks. Not to mention saddle sores. One copes. Or one doesn't. In that case, one buys a golf cart and a season pass to Disney World.

I usually ride a size 52 frame, and on my fixed gear 700c road bike I have deal with pretty major toe clip overlap with the fenders AND the tire. Even though its fixed and hard to time slow speed turns sometime with the overlap, the overall frame handles great. It has a low trail but high headtube angle, and I love the responsive steering.

I'm with those who say minimal tco is only an issue fixed, otherwise coast. I do brush my fenders on my fendered fixed bad weather bike, but only went down once: stupid Planet Bike fenders' struts extend past the fenders and caught on my winter neoprene shoe covers. I bent those strut ends downwards and have been fine since.

On the other hand, as a small footed, 6'1" on a 59cm frame, I'm only ever going to have the issue on my fendered bike with track geometry. Short people with big feet will want smaller wheels and relaxed geometry.

My new Waterford commuter frame with TCO is dangerous to track stand or maneuver in traffic. For urban commuters, TCO is not the equivalent of helmet hair!

Unless a frame is intended for racing or for small riders, builders are obligated to provide pedal clearance or give the buyer fair warning. I'm 5'9" and my other bikes offer adequate pedal clearance.

The Waterford does not meet the reasonable Consumer Product clearance from the pedal to either the fender or even the tire:

16 C.F.R. Part 1512(4) Bicycles without toe clips must have pedals that are at least 3 ½ inches from the front tire orfender when the front tire is turned in any direction [measured from pedal center].

I would agree that TCO is something that should be minimized when designing most 'non-racing' frames, but let's remember that you can't always guarantee that it won't occur somewhere 'down the road' in the life of the frameset. If someone puts 185 mm cranks, XL toeclips spaced forwards with extra washers, 35 mm 700C (or even wide 27-inch) tires, and 50 mm fenders on a medium-to-large sized old racing bike, that might create substantial TCO!